Abdullah , Khalid I., and Nafya H. Mohammed. “Estimates of Coefficients for Bi-Univalent Functions in the Subclass H_∑ (n,γ,φ)”. Tikrit Journal of Pure Science, vol. 28, no. 4, Aug. 2023, pp. 80-87, doi:10.25130/tjps.v28i4.1531.